The invention relates to an articulated arm for an awning, with an articulation part and with an arm profile which are inserted one into the other and which are provided with pull-off protection.
The invention relates, furthermore, to a method for the production of an articulated arm of an awning, in which an articulation part and an arm profile are inserted one into the other and are protected against being pulled off from one another.
Articulated arms are in widespread use in shading installations and serve, for example, for guiding an awning cloth when the latter is moved in or out. Such an articulated arm consists of an arm profile, usually a hollow profile, to the ends of which articulation parts are attached. The articulation parts usually have a tenon which is driven into the interior of the hollow profile. The awning arm is mounted in an articulated manner, that is to say moveably, by means of the articulation part.
Depending on the configuration of the awning, this is a single awning arm pivotable out of an upright position into a tilting position, for example in the case of sun-blinds, or a collapsible arm composed of two articulated arms, in the case of collapsible-arm awnings which move out and in essentially horizontally or at a downward inclination. Awnings are structures which have a very long useful life, a lifetime of ten, fifteen and twenty years being customary.
Furthermore, during this period of time, awnings are exposed to rough environmental conditions, since they are normally mounted on the outsides of buildings. When the awnings are moved out and in, particularly where collapsible-arm awnings are concerned, considerable forces act on the connection between the articulation part and arm profile, considerable tensile or compressive forces acting alternately on the components pushed one into the other when the awnings are moved out and in.
Care must therefore be taken to ensure that there is pull-off protection which permanently prevents the arm profile from being pulled off from the articulation part.
It became known to implement the pull-off protection by means of a screw connection or a clinch bolt which extend transversely with respect to the insertion direction through the arm profile and the tenon, pushed into the latter, of the articulation part.
This pull-off protection has the disadvantage that it is visible from outside and forms a point where unsightly dirt accumulations or possibly corrosions may occur, so that even moisture and dirt can penetrate into the interior of the arm profile. Inside the arm profile are received tension devices, such as springs, ropes, chains of the like. Conventionally, the arm profile and articulation part are produced from aluminum or aluminum alloys which are corrosion-resistant. However, the screws or bolts are produced from ferrous materials and tend, particularly in long-term use, to corrosion.
The adhesive bonding technique was therefore adopted for connection purposes. In this case, the dimension of the tenon, to be pushed into the arm profile, of the articulation part was selected such that it has a sufficient undersize to introduce all adhesive between the outside of the tenon and the inside of the arm profile.
Particularly in the case of collapsible-arm awnings, which often have a width of several meters and also drop lengths of several meters, the outer drop rod should be in exactly parallel alignment with the housing carrying the winding shaft, both in the extended and in the retracted state. Angular deviations out of this parallel alignment of only one or two degrees lead, in the case of extremely wide awnings, to an unsightly skewing in alignment between the drop rod, whether it is retracted or extended, and the housing.
All the abovementioned manufacturing methods have some relatively high inaccuracy factors due to tolerances and angular errors, and it is highly complicated to implement the connection during manufacture.
In adhesive bonding, the arms have to be held and oriented, for example, in a special holding machine, and it is necessary to wait until the adhesive compound has cured completely.
In connection by means of rivets or screws, after the arm profile has been attached or pushed onto the articulation part corresponding bores have to be made and the screws or rivets inserted into these.
This is highly time-consuming and is a considerable impediment to the manufacturing flow.
Awning manufacturers endeavor to dispatch the individual parts, particularly in the case of international sales networks, to the distributors who then have to carry out the final manufacture of the articulated arms at a correspondingly high outlay.
It is an object of the invention to remedy this and to provide an articulated arm and a method for the production thereof, which is simple to carry out and ensures a permanently reliable, in particular pull-off protected connection between the arm profile and articulation part.